Indexing tool turrets are used to automate the changing of rotary tools that are driven by a spindle motor. A tool turret can hold several, (e.g., a dozen or even more) separate tools and rotate to selectively align a desired tool with a driving shaft of a spindle motor. The motor connects to a driven shaft and live toolholder via gears and a clutch. In conventional turrets, there typically is not much room inside the top plate assembly for a direct drive. Therefore, many live tool drives for turrets use a transmission shaft having gears that transmit power at approximately a 90° angle to the axis of rotation of the toolholder. For example, see U.S. Pat. No. 6,785,943, herein incorporated by reference.
The present invention provides several different improvements over this known prior art.